My rear diff housing theory

[LightForce]

Ok i reinforced the rear housing and added 3mm chassis plate to support rear from bending and guess what front housing broke on brand new XB not even began to push hard yet.

 

[cordy]

Sorry to hear that Mike. I wonder why the housings arent breaking in china? The only differance I see is in china I believe thier just bashing on the test site,were as we are raceing them on the track. Perhaps if they would start testing under race conditions they would start poping thier housings. I also would wonder if anybody in europe are raceing the xb`s if thier having problems with thier housings? Any way I got the fg lepoard ready to go,I havent started it yet.Without fuel it weighs 24.4 lbs. I know Johnos wants to try it.

 

[k.jensen]

Sorry to hear that Mike. I wonder why the housings arent breaking in china? The only differance I see is in china I believe thier just bashing on the test site,were as we are raceing them on the track. Perhaps if they would start testing under race conditions they would start poping thier housings. I also would wonder if anybody in europe are raceing the xb`s if thier having problems with thier housings? Any way I got the fg lepoard ready to go,I havent started it yet.Without fuel it weighs 24.4 lbs. I know Johnos wants to try it.

yurp. we are a few that are racing the XB's here in europe (denmark)

some peeps have trouble, but I myself have only had ONE incident with the housings, a blown bearing ate the plastic housing. not like the srouble u guys have had.

 

[DemonRC]

I have some more data to add to the mix. My brace has been holding great for two weekends now. I haven't ripped the pinion gear out of the diff. Everything was great untill I cartwheeled from hitting a rut. Not more that 3-4 minutes after that I lost rear wheel drive because my pinion was moving around. It turns out that the inner bearing slot stretched out which let the pinion move too much and ended up grinding gears.

 

[k.jensen]

I have some more data to add to the mix. My brace has been holding great for two weekends now. I haven't ripped the pinion gear out of the diff. Everything was great untill I cartwheeled from hitting a rut. Not more that 3-4 minutes after that I lost rear wheel drive because my pinion was moving around. It turns out that the inner bearing slot stretched out which let the pinion move too much and ended up grinding gears.

yurp, the plastic is way to soft for the heat from the bearings. same thing happend to me with one of the other bearings in the gearbox

 

[LightForce]

I have some more data to add to the mix. My brace has been holding great for two weekends now. I haven't ripped the pinion gear out of the diff. Everything was great untill I cartwheeled from hitting a rut. Not more that 3-4 minutes after that I lost rear wheel drive because my pinion was moving around. It turns out that the inner bearing slot stretched out which let the pinion move too much and ended up grinding gears.

I lost one front and couple of rears so far come on Redcat we need those V2 housings with bigger bearings asap .

 

[cordy]

Well lets go old fart,we need those housings and so does europe. I am not even going to run my xb till those houseings are ready,cuz I don't like takeing my xb apart. Iam thinking of getting a neutech tb3 for a back up. The last I heard the newys were beating the mcd`s in europe. I want to race my xb but I don't want it down either.

 

[DemonRC]

We're gonna find out if I'm correct on this very soon. I'm pounding the crap outta my XBE. The crap I was doing today would eat a rear diff in a weekend in my XB. The difference is that the XBE has some major bracing from the rear all the way to the motor. It's freaking rock solid. I have a backup case ready so I was landing WOT at least two dozen times today. I'll pound on it again tommorrow on this one jump and check for any wobble in the rear pinion after the weekend.

 

[cordy]

Thanks Demon.

 

[DemonRC]

Diff is still on good condition. I get to work outta the house tommorrow so I'll pound on it for another hour tommorrow.

 

[bbuzzard]

These diff housing issues are very similar to my MCD problems in the rear...which happened twice and then I realized I need to stop bashing the big beast so hard. Ever since, no problem. Watching my throttle on jumps has eliminated those problems. FYI - I have been running that thing for a year with no problems. Also, I haven't had any front or rear diff issues...I'm actually waiting for my bearings to fail to test out some Boca bearings at the wheels.

 

[DemonRC]

After my last grinded diff in my XB, I've been running my XBE which is holding up well. I can't break the dam diff in that thing. Even with the stock motor it's got mad torque that makes my 30.5 TS motor look like a joke. Well I just got through tearing my XB down to take a look and the failure wasn't from the pinion gear shaft flopping around. I had one of my diff cup bearings explode. It was a a stock bearing and took 18 months of abuse so I guess it was about time for it to go. Well the diff was flopping around which was why I was grinding gears.

Back to beating on the XBE. I'll run two packs tommorrow (20 minutes each) and be jumping my favorite bank the whole time. I don't let off the throttle with the XBE because it's neato to wheelie. I have a spare rear diff housing handy so I'll still be trying to break that sonnofabitch.

 

[nitrohobbiest]

I figured I would chime in here just so you can see the numbers of diff housing fatalities because I also busted one wide open today only 5 minutes into my first successful run with this truck. Everything was working great and then boom, front wheel drive again. Usually its a grub screw that loosens up but not this time! Being that you guys have not had luck just replacing it, I'm going to look into beefing up a new one or rebuilding my old one. I made a steel tube roll cage that bolts straight to the shock tower and stops past the engine so now I'm thinking I need to extend it to the front tower to beef up the whole truck. My original intent was just to protect the spark plug but now I have a new goal.

 

[big JC]

Question, does the xbe and xb/xt have identical bearings in the difs? I know demon was set on the idea that the failures were do to flex but now you found a bearing that ate itself. Maybe that area is cracking do to much heat from the bearing which can make the plastic brittle? Of coarse I am e-speculating here as I don't own one. Wondering if just changing out the bearings to better quality ones might cure some problems? I am on the fence between the xt & mt and am looking to pull the trigger on one asap. A really want the xt but not if there is no good solution on the dif case. This will be my first rc in 20 years and I am really excited about getting back into it!